The invention concerns a torsionally elastic clutch wherein the clutch halves are nested in disk fashion and have cutouts which house tangentially arranged helical springs. A guide body is located on the outer peripheral area of the individual spring in order to prevent buckling of the spring. Typically, the guide body is shorter than the spring. A clutch of this type is known from German patent disclosure 36 35 043.5.
Torque is introduced from one clutch half, which for instance is mounted directly on the flywheel of the drive engine, at one end of each of the tangentially arranged springs and transmitted from their other ends to the other clutch half. The spring ends are usually installed in suitable components for centering within cutouts provided in the clutch halves. The elasticity and the vibration or damping performance of the clutch can be influenced by suitable dimensioning of the springs, which are compressed under the effect of the torque.
The guide body between the radially outer area of the respective helical spring and the radial outer defining surface of the cutout prevents the spring from bowing outward. The guide body occupies the space between these surfaces, at least in the center area of the length of the spring. Thus, the spring retains its straight-line shape and its characteristics at a high speed of rotation, without local overstressing or disturbance in the absorption of the torque.
In the contact area with the spring, the guide body may feature a concave rounding that matches the diameter of the spring, in order to assure good guiding of the spring, and may include surfaces for guiding on the radially outer defining edge of the cutout for the spring or on the inner defining walls of the clutch. Being shorter than the spring length, the guide body is mostly located in the center area of the spring. In the operation of the clutch it shifts then toward one spring end, where it binds very quickly. Naturally, its effectiveness is greatly reduced thereby.
Proposed as a means to prevent buckling is a bolt that is looped by the windings of the spring. When making the bolt shorter than the spring, the same problem as described above will occur. But when making the bolt longer and permitting it to protrude beyond the spring ends and into the guide sleeves, such will be at the expense of design length, which is not always available. Thought might also be given to using an outer or inner guide body and giving it a telescopic design, so that it will perform its function also with the spring compressed. However, such a solution would result in a very expensive construction. The problem underlying the invention is to so design a torsionally elastic clutch of the general type discussed above that the individual springs will not bow out outwardly but will always maintain their alignment and that the manufacturing costs as well as the susceptibility to malfunction will be kept low.